Changeset 0ab362c in mainline for kernel/arch/arm32/include/asm.h

Timestamp:

2012-11-22T14:36:04Z (12 years ago)

Author:

Jan Vesely <jano.vesely@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

e32720ff

Parents:

1f7753a (diff), 0f2c80a (diff)
Note: this is a merge changeset, the changes displayed below correspond to the merge itself.
Use the (diff) links above to see all the changes relative to each parent.

Message:

Merge support for BeagleBoard-xM (armv7).

Most of the changes outside arm arch are pio_* stuff (addition of pio_trace capability, header consolidation)

File:

• kernel/arch/arm32/include/asm.h (modified) (1 diff)

kernel/arch/arm32/include/asm.h

@@ -43 +43 @@
 #include <trace.h>
 
-/** No such instruction on ARM to sleep CPU. */
+/** No such instruction on old ARM to sleep CPU.
+ *
+ * ARMv7 introduced wait for event and wait for interrupt (wfe/wfi).
+ * ARM920T has custom coprocessor action to do the same. See ARM920T Technical
+ * Reference Manual ch 4.9 p. 4-23 (103 in the PDF)
+ */
 NO_TRACE static inline void cpu_sleep(void)
 {
+#ifdef PROCESSOR_armv7_a
+        asm volatile ( "wfe" :: );
+#elif defined(MACHINE_gta02)
+        asm volatile ( "mcr p15,0,R0,c7,c0,4" :: );
+#endif
 }